1. Field of the invention
The present invention relates to an air bag control system for passenger seats and, more particularly, to an air bag control system for passenger seats for controlling the deployment of an air bag in correspondence with the conditions of an occupant in the passenger seat.
2. Description of Related Art
It is known to equip vehicles with an air bag control system for passenger seats for protecting an occupant in the passenger seat at the time of an emergency. Such a control system is described in Japanese patent application laid-open No. Hei 8-268220, which as filed in the U.S. issued as U.S. Pat. No. 5,702,123.
An air bag control system for passenger seats, as shown in FIG. 8 and described in detail in that U.S. Pat. No. 5,702,123, has an occupant detecting sensor 106 that is mounted on a ceiling 100. The mount position of the occupant detecting sensor 106 is above a point between an instrument panel 102 and a seat back 104. The detection area A of the occupant detecting sensor 106 extends over legs 110A of an occupant 110 seated in a passenger seat 108. An approach detecting sensor 112 is provided forward from the occupant detecting sensor 106. The detection area B of the approach detecting sensor 112 extends above the instrumental panel 102, that is, to a position that is a predetermined distance apart therefrom. If the distance detected by the approach detecting sensor 112 is at most a predetermined distance L, an air bag control circuit 114 determines that a child 116 is in a standing posture. If the detected distance is greater than the predetermined distance L, the air bag control circuit 114 determines that an adult 118 has stretched out his/her arm 118A to the instrument panel 102 (that is, a protective arm position).
With regard to such an air bag control system for passenger seats, there is a need for more reliable determination on the sitting or standing conditions of the adult 118 and the child 116 in the vehicle in order to achieve optimal occupant protection.